One function of a shoe is to protect and support the foot. To this end, a shoe, typically an athletic shoe, includes a sole to provide traction, support and cushioning. A shoe typically also includes an upper that is stitched and/or glued to the upper periphery of the sole. The upper is intended to hold the foot of the wearer to the sole, provide a tight and comfortable fit, and prevent sliding of the foot within the shoe. Sliding can occur when the upper does not properly conform to the foot leaving gaps between the foot and the upper, or when the upper has insufficient stiffness and deflects under loading. Sliding of the foot in the shoe may result in inefficient performance, instability, discomfort and injury.
Uppers are typically constructed of leather and other materials having properties similar to leather. Leather and other similar materials are inherently stiff and usually provide the necessary rigidity for supporting a foot in the shoe. However, the high stiffness of the leather can cause the wearer discomfort and adversely affect the shoe's ability to conform to the foot thereby affecting the performance of the wearer. Since an upper made from leather is heavy and thick, it requires a break-in period to gain flexibility. Additionally, leather materials may also be disadvantageous because they retain moisture and do not permit the foot to breathe.
The disadvantages of leather and leather-like materials for shoe upper construction led to the development of uppers constructed at least in part of various synthetic materials. Most of these synthetic materials are polymer meshes that are light and breathable. Meshes can be advantageous in athletic shoes where a lightweight shoe is important to the athlete's performance during athletic activities, e.g., running and walking events. The mesh also allows the foot to breathe thereby keeping the foot relatively dry during athletic activities. However, the same flexible qualities of the synthetic mesh materials renders them less than ideal in their role of tightly supporting the foot, especially under the large loading forces that are present during athletic activities.
More recently, hybrid-type uppers have been used that are constructed of a combination of the lightweight, more flexible, synthetic materials and stiffer materials such as leather straps and panels for reinforcement. Other shoes with hybrid-type uppers have used a stiff leather counter immediately above the sole and synthetic material stitched to the top of the counter. These shoes can be beneficial over shoes made completely of leather by increasing flexibility/breatheability and decreasing weight. However, these hybrid-type uppers still are comprised of a large percentage of overly stiff and heavy materials and are a suboptimal compromise of support, flexibility and breatheability.
The prior art also includes uppers which have one or more plastic or rubber elements melted to a sock structure. Uppers of this type are shown in U.S. Pat. Nos. 2,147,197 and 4,447,967. However, none of these uppers has developed the fulll advantages of the different components. Accordingly, an improved shoe upper for an article of footwear was needed.